Which of the following countries have not accepted Euro as the common currency?

The correct option is Denmark and Sweden.

To understand why this is the correct choice, let us look at the status of each pair of countries listed in the options with respect to the Eurozone:
1. Denmark and Sweden: Both Denmark and Sweden are members of the European Union (EU) but have not adopted the Euro as their currency. Denmark negotiated an opt-out from the Eurozone in the Maastricht Treaty and continues to use the Danish krone (DKK). Sweden, although legally obligated to join the Eurozone eventually, has not yet joined the Exchange Rate Mechanism (ERM II) and continues to use the Swedish krona (SEK) following a public referendum in 2003.
2. Spain and Portugal: Both countries adopted the Euro on January 1, 1999 (for electronic transactions) and introduced Euro coins and banknotes in 2002.
3. Greece and Germany: Germany was one of the founding members of the Eurozone in 1999, and Greece adopted the Euro in 2001.
4. France and Austria: Both countries adopted the Euro as founding members of the Eurozone in 1999.

Therefore, Denmark and Sweden are the countries among the choices that have not accepted the Euro as their common currency.